A recent survey by US health authorities suggests that about a quarter of American teenage girls have been vaccinated against HPV, the human papillomavirus, which is estimated to cause most cervical cancers.
According to Reuters news agency, the US Centers for Disease Control and Prevention (CDC), announced to the press on Thursday that a nationwide survey of about 3,000 girls showed that about 25 per cent of the nation’s adolescent female population (that is about 2.5 million girls) aged 13 to 17 got at last one of the three shots that comprise Merck’s Gardasil vaccine.
The survey was the first attempt to establish how widely the vaccine has reached. Gardasil was approved by the Food and Drug Administration (FDA) just over two years ago. The vaccine is used to prevent cervical cancer and genital warts and is aimed at women and girls aged from 9 to 26 years.
The CDC was pleased with the figure, but recognized there was still a long way togo. As Dr. Lance Rodewald, who is head of the agency’s division of immunization services told reporters during a conference call:
“It generally takes about seven or eight years before you can go from a new vaccine all the way to having 90 percent coverage rate, which would be the eventual target.”
The CDC does not have any information on how many older women (from 18 to 26) have taken up the vaccine.
HPV is a family of 100 or so common sexually transmitted viruses that cause genital warts and cervical cancers. The Gardasil vaccine protects uninfected women against infection by four strains of HPV which are thought to be responsible for over 70 per cent of cervical cancers.
According to Reuters, over 18 million doses of Gardasil have been distributed in the US and Merck expects sales in 2008 to reach 1.6 billion dollars.
The CDC recommends that girls get vaccinated at the age of 11 or 12, because once they are sexually active they are more likely to become infected with HPV and the vaccine doesn’t have any effect after that. The other advantage of having the vaccination at the age of 11 is that this is the age when children receive a lot of other shots.
According to the National Cancer Institute, in 2008 in the US there will be 11,070 new cases of cervical cancer and 3,870 deaths to the disease.
A National Health and Nutrition Examination Survey (NHANES) published in the Journal of the American Medical Association (JAMA) last year estimated that 27 per cent of women aged 14 to 59 in the US are infected with one or more strains of HPV.
A Johns Hopkins University associate professor of epidemiology, Patti E Gravitt, told Associated Press that families were wary about new vaccines, and there are other barriers to this one in particular. For a start there is the cost, at around 375 dollars, although more insurance companies are now covering it. There are also questions about whether a booster shot is needed later on in life.
Merck was reported to be pleased with the survey results.
Another HPV vaccine, Cervarix, made by GlaxoSmithKline, is expected to win FDA approval next year.
Source: AP, Reuters, NCI.
Written by: Catharine Paddock, PhD.